In a remote “keyless” entry system for an automobile, the automobile operator usually carries an electronic “key” device along with the mechanical key for the automobile. The electronic key device has several buttons allowing the operator to perform different functions traditionally requiring the mechanical key. For example, the key device usually includes a button for locking the doors, a button for unlocking the doors, and a button for opening the trunk. Some electronic key devices also include a button for starting the engine of the automobile and a button for triggering/terminating an alarm condition of an alarm system on the automobile.
When a particular button is pressed, the electronic device emits a radio wave having a specific frequency. Based on the frequency, a controller onboard the automobile is able to discern and execute a requested command. Since radio waves are used, the operator can perform the various functions at a distance from the automobile (e.g., several meters). For example, the operator can start the automobile while still inside a building or can unlock the doors while walking through a parking lot to the automobile.
While conventional keyless entry systems are useful, they have certain drawbacks. For example, since the operator usually carries the electronic key with the mechanical key, electronic keys are not convenient in terms of reducing the number of items that must be carried when taking a trip in the automobile. Further, the mechanical key is usually lost when the electronic key is lost. And replacing the electronic key or the mechanical key is time-consuming, inconvenient, and expensive. Further, conventional keyless entry systems are limited in terms of their functionality.
This disclosure is directed to overcoming one or more of the problems set forth above, as well as other problems in the art.